Education

Research Description

Dr. Barlaz has been involved in research on various aspects of solid waste since 1983. Over this time, he has conducted research on biological refuse decomposition, methane production, and the biodegradation of hazardous wastes in landfills.  He has participated in two state-of-the-practice reviews of bioreactor landfills.  His research forms the basis for much of the work done to assess the impact of landfills on methane emissions inventories.  Dr. Barlaz is also recognized for his research on the use of life-cycle analysis to evaluate environmental emissions associated with alternate solid waste management strategies.

Publications

An Assessment of the Dynamic Global Warming Impact Associated with Long-Term Emissions from Landfills

Wang, Y., Levis, J. W., & Barlaz, M. A. (2020), ENVIRONMENTAL SCIENCE & TECHNOLOGY, 54(3), 1304–1313. https://doi.org/10.1021/acs.est.9b04066

The impact of pressure, moisture and temperature on pyrolysis of municipal solid waste under simulated landfill conditions and relevance to the field data from elevated temperature landfill

Tupsakhare, S., Moutushi, T., Castaldi, M. J., Barlaz, M. A., Luettich, S., & Benson, C. H. (2020), SCIENCE OF THE TOTAL ENVIRONMENT, 723. https://doi.org/10.1016/j.scitotenv.2020.138031

Approaches to fill data gaps and evaluate process completeness in LCA-perspectives from solid waste management systems

Henriksen, T., Levis, J. W., Barlaz, M. A., & Damgaard, A. (2019), INTERNATIONAL JOURNAL OF LIFE CYCLE ASSESSMENT, 24(9), 1587–1601. https://doi.org/10.1007/s11367-019-01592-z

Evaluation of optimal model parameters for prediction of methane generation from selected US landfills

Sun, W., Wang, X., DeCarolis, J. F., & Barlaz, M. A. (2019), WASTE MANAGEMENT, 91, 120–127. https://doi.org/10.1016/j.wasman.2019.05.004

Improving understanding of carbon storage in wood in landfills: Evidence from reactor studies

Ximenes, F. A., Bjordal, C., Kathuria, A., Barlaz, M. A., & Cowie, A. L. (2019), WASTE MANAGEMENT, 85, 341–350. https://doi.org/10.1016/j.wasman.2019.01.004

Solid Waste Management Policy Implications on Waste Process Choices and Systemwide Cost and Greenhouse Gas Performance

Jaunich, M. K., Levis, J. W., DeCarolis, J. F., Barlaz, M. A., & Ranjithan, S. R. (2019), ENVIRONMENTAL SCIENCE & TECHNOLOGY, 53(4), 1766–1775. https://doi.org/10.1021/acs.est.8b04589

Carbon dynamics of paper, engineered wood products and bamboo in landfills: evidence from reactor studies

Ximenes, F. A., Kathuria, A., Barlaz, M. A., & Cowie, A. L. (2018), CARBON BALANCE AND MANAGEMENT, 13. https://doi.org/10.1186/s13021-018-0115-3

Case study comparison of functional vs. organic stability approaches for assessing threat potential at closed landfills in the USA

O'Donnell, S. T., Caldwell, M. D., Barlaz, M. A., & Morris, J. W. F. (2018), Waste Management (New York, N.Y.), 75, 415–426. https://doi.org/10.1016/j.wasman.2018.02.001

Methods of Responsibly Managing End-of-Life Foams and Plastics Containing Flame Retardants: Part I

Lucas, D., Petty, S. M., Keen, O., Luedeka, B., Schlummer, M., Weber, R., … Koshland, C. P. (2018), Environmental Engineering Science, 35(6), 573–587. https://doi.org/10.1089/ees.2017.0147

Microbial ecological succession during municipal solid waste decomposition

Staley, B. F., de los Reyes, F. L., Wang, L., & Barlaz, M. A. (2018), Applied Microbiology and Biotechnology, 102(13), 5731–5740. https://doi.org/10.1007/s00253-018-9014-5

View all publications via NC State Libraries

Grants

Development of a Perfluoroalkyl Substances (PFAS) Systems Analysis Tool (SAT) to Assist in Prioritization of Destruction Research and Management Decisions

US Environmental Protection Agency (EPA)(6/11/20 - 9/30/20)

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Development of a Perfluoroalkyl Substances (PFAS) Systems Analysis Tool (SAT) to Assist in Prioritization of Destruction Research and Management Decisions

Sponsor: US Environmental Protection Agency (EPA)

Start Date: 6/11/20

End Date: 9/30/20

Abstract

The objective of this project is to develop a comprehensive systems analysis tool (SAT) to estimate PFAS release associated with management alternatives for a wide range of PFAS-containing wastes. Through this project, we will establish an analytical framework to rigorously describe alternatives for the management of individual PFAS-containing wastes, estimate PFAS release and the receiving medium (air, surface water, groundwater, land).

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Anaerobic Decomposition of Cotton Fabric Under Simulated Landfill Conditions

Cotton, Inc.(1/01/20 - 12/31/20)

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Anaerobic Decomposition of Cotton Fabric Under Simulated Landfill Conditions

Sponsor: Cotton, Inc.

Start Date: 1/01/20

End Date: 12/31/20

Abstract

The US EPA estimates that only about 15% of textiles were recovered for recycling in 2015 while 66% of textiles were disposed in landfills. Textiles that are manufactured from cotton represent an important component of the overall textile market. Cotton is comprised largely of cellulose and, under the anaerobic conditions that dominate landfills, cellulose is converted to methane and carbon dioxide. An understanding of the anaerobic biodegradability of cotton as used in various types of textiles is important to characterize the carbon footprint of cotton-based textiles in landfills. While there is considerable literature on the anaerobic biodegradability of a number of lignocellulosic substrates in landfills, including various types of paper, lumber, food waste, grass, leaves and branches, there is only limited literature on the anaerobic biodegradability of cotton and neither study was conducted under conditions that are designed to simulate a landfill. Methane and carbon dioxide are the ultimate endproducts of anaerobic biodegradation in landfills. The methane is particularly important because it is both a potent greenhouse gas as well as an energy source. There are several fates for the methane produced in landfills. Some methane is released to the atmosphere because gas collection systems are not 100% efficient and some methane is produced prior to gas collection system installation. In addition, landfills below EPA-described capacity levels are not required to collect landfill gas. Methane that is captured may be converted to energy (engines, turbines, boilers) in which case the landfill can claim credit for avoided emissions associated with energy generation from traditional sources. Finally, some methane is captured and converted to carbon dioxide in a flare with no energy recovery. To the extent that biogenic carbon (e.g., cotton) is not completely degraded, the undegraded carbon represents stored carbon. Carbon storage and the fate of methane are dominant factors in a landfill carbon balance. The objectives of the proposed study are to (1) evaluate the rate and extent of anaerobic decomposition of three types of cotton fabric under simulated landfill conditions and (2) compare the decomposition behavior of cotton fiber with a synthetic polyester. Three types of cotton will be tested including a bleached cotton fabric and cotton fabric with softer and durable press finishes. In addition, a synthetic fabric polyester will be tested. Materials will be tested in 8-L reactors that are operated to simulate optimal conditions in a landfill such that the results will represent the ultimate extent of biodegradation expected in a landfill. Reactor operating conditions include (1) incubation in a room at 37 ï‚°C, the optimal temperature for mesophilic waste decomposition, (2) addition of moisture and leachate recirculation to promote the distribution of microorganisms and substrate, and (3) maintenance of critical nutrients (N and P) at concentrations that will not inhibit waste decomposition. In addition, reactors will be inoculated with well decomposed refuse that is maintained in our laboratory. A mass balance will conducted at the end of the decomposition cycle by comparing the mass of added test material (as methane potential) to the measured methane and carbon dioxide and residual material. In addition, cotton fabric residue showing visible signs of decomposition will be used to explore how fiber morphology and crystallinity changes correlate with results of chemical and biochemical analyses. Changes in fiber morphology will be evaluated by scanning electron microscope (SEM) to measure changes is surface characteristics of samples that contain different types of finish. XRD will be used to evaluate changes in cotton cellulose crystallinity to evaluate the relationship between crystallinity and biodegradability.

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Center for Environmental and Health Effects of PFAS

National Institutes of Health (NIH)(2/28/20 - 1/31/21)

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Center for Environmental and Health Effects of PFAS

Sponsor: National Institutes of Health (NIH)

Start Date: 2/28/20

End Date: 1/31/21

Abstract

Per- and polyfluoroalkyl substances (PFAS) are emerging as a major public health problem in North Carolina and across the United States. PFAS comprise a class of over 5,000 compounds. Their unique chemical properties have been harnessed to make consumer and industrial products more water, stain, and grease resistant; they are found in products as diverse as cosmetics and flame-retardants. PFAS are resistant to degradation, move easily through the environment, and accumulate in living organisms. Exposure to PFAS has been associated with health effects including cancer and toxicity to the liver, reproductive development, and thyroid and immune systems. Despite widespread detection in the environment and evidence of increasing human exposure, understanding about PFAS toxicity, its bioaccumulative potential in dietary sources such as aquatic organisms, and effective remediation remain notably understudied. The recent discovery by this proposed Center’s Deputy Director, Dr. Detlef Knappe, of widespread PFAS contamination in the Cape Fear River watershed in NC underscores that these compounds are in need of immediate investigation.. The goal of our Center is to advance understanding about the environmental and health impacts of PFAS. To meet this goal we are employing a highly trans-disciplinary approach that will integrate leaders in diverse fields (epidemiology, environmental science and engineering, biology, toxicology, immunology, data science, and advanced analytics); all levels of biological organization (biomolecule, pathway, cell, tissue, organ, model organism, human, and human population); state-of-the-art analytical technologies; cutting-edge data science approaches; a recognized track record in interdisciplinary, environmental health science (EHS) training; and well-established partnerships with government and community stakeholders.

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Characterization and Quantification of Per- and Polyfluoroalkyl Substances in Landfill Gas and Estimate of Emissions from U.S. Landfills

US Environmental Protection Agency (EPA)(9/01/19 - 8/31/22)

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Characterization and Quantification of Per- and Polyfluoroalkyl Substances in Landfill Gas and Estimate of Emissions from U.S. Landfills

Sponsor: US Environmental Protection Agency (EPA)

Start Date: 9/01/19

End Date: 8/31/22

Abstract

The overall objective of the proposed research is to develop an estimate of the mass of PFASs that are present in LFG and to begin to develop information the factors that impact their release. The proposed research will include measurements at full-scale landfills as well as measurements in lab scale reactors to understand trends in PFAS release during the decomposition cycle, the impact of waste age on PFAS concentrations and the impact of soil attenuation on PFAS release.

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Development of Test Methods to Characterize Heat Production from Special Wastes Disposed in Landfills

Environmental Research & Education Foundation(9/01/18 - 9/01/21)

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Development of Test Methods to Characterize Heat Production from Special Wastes Disposed in Landfills

Sponsor: Environmental Research & Education Foundation

Start Date: 9/01/18

End Date: 9/01/21

Abstract

Recently, there have been reports of municipal solid waste (MSW) landfills that have been experiencing temperatures in excess of 80 °C. Elevated temperatures have a number of deleterious effects that are well known to landfill owners. Consequently, elevated temperature landfills often require increased monitoring and management. In recent work supported by the EREF, we developed a model of heat accumulation in a landfill. The objective of the model was to help identify and mathematically describe all sources of heat input, generation and loss in a typical Subtitle D landfill. The model simulations identified several reactions that contribute significant heat to landfills including the hydration and carbonation of calcium-containing wastes (e.g., ash) and aluminum corrosion. Model predictions however, were based on information adopted from the literature for systems other than landfills. In addition to MSW, many landfills receive non-hazardous industrial wastes including ash from both coal and MSW combustion, ash used to solidify liquid wastes, auto shredder residue (ASR) that contains Al and Fe, and perhaps other Al-containing wastes. Methods are needed to measure the heat production potential of such wastes under landfill-relevant conditions and to use the resulting heat production data to evaluate the quantity of a given waste that can be disposed without the accumulation of unacceptable heat. The objectives of the proposed research are to (1) develop laboratory methods to measure heat evolution from special wastes under landfill-relevant conditions and (2) measure rates of heat production to parameterize our heat accumulation model. The model will then be used to estimate acceptable quantities of specific heat-producing wastes for disposal. The proposal emphasizes heat release from ash and metal corrosion. However, methods will be generalized to assess the heat generation of other wastes.

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Development of a Life-Cycle Model for Open Dumps and Informal Waste Collection

RTI International (aka Research Triangle Institute)(10/14/16 - 9/30/17)

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Development of a Life-Cycle Model for Open Dumps and Informal Waste Collection

Sponsor: RTI International (aka Research Triangle Institute)

Start Date: 10/14/16

End Date: 9/30/17

Abstract

RTI International, in partnership with North Carolina State University, developed and successfully deployed the Municipal Solid Waste Decision Support Tool (MSW DST) to assist cities and stakeholders in evaluating the cost and environmental trade-offs for alternative MSW management strategies and technologies. The MSW DST has been used on numerous projects for federal, state, and local government agencies as well as the solid waste industry over the last decade. The existing MSW DST was developed for U.S. domestic application and modifications are needed to more fully meet the needs of the international cities. The goal of this project is to develop and implement enhancements to the MSW DST to strengthen its applicability to waste management issues facing many international developing and transition economies including topics such as the open dumping and burning of waste and creating local economic development opportunities via recycling and composting. To achieve the goal, new modules (Excel-based models) to quantify the cost and environmental emissions for identified waste management activity gaps need to be built and integrated into the MSW DST.

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Development of a Predictive Model to Estimate Emissions from Open Dumps in Emerging Economies

Procter & Gamble(3/17/15 - 12/31/17)

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Development of a Predictive Model to Estimate Emissions from Open Dumps in Emerging Economies

Sponsor: Procter & Gamble

Start Date: 3/17/15

End Date: 12/31/17

Abstract

The overall objective of this study is to develop a model of the behavior of packaging and other consumer products when disposed in open dumps to estimate emissions to the environment (surface water, groundwater, air, soil). The model will utilize the principles of life-cycle assessment (LCA) and will be designed with a large degree of flexibility so that it can respond to a variety of scenarios that range, for example, from open dumps in wet versus arid conditions to landfills with either some or a high degree of engineered controls.

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Maximizing Energy for Waste While Minimizing Life-Cycle Environmental Burdens and Cost

US Environmental Protection Agency (EPA)(12/09/14 - 11/30/19)

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Maximizing Energy for Waste While Minimizing Life-Cycle Environmental Burdens and Cost

Sponsor: US Environmental Protection Agency (EPA)

Start Date: 12/09/14

End Date: 11/30/19

Abstract

The US EPA is interested in developing a next generation tool for sustainable materials management as an update to the current Municipal Solid Waste Decision Support Tool (MSW DST). As part of this task, RTI International (RTI) will conduct a review the current SWOLF software tool being developed at North Carolina State University (NCSU) and assess the work required to convert the tool into a stand-alone desktop application, similar to the MSW DST.

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UNDERSTANDING AND PREDICTING TEMPERATURES IN MUNICIAPL SOLID WASTE LANDFILLS

Environmental Research & Education Foundation(12/15/14 - 6/30/19)

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UNDERSTANDING AND PREDICTING TEMPERATURES IN MUNICIAPL SOLID WASTE LANDFILLS

Sponsor: Environmental Research & Education Foundation

Start Date: 12/15/14

End Date: 6/30/19

Abstract

The objective of this study is to critically analyze existing literature on hot landfills.

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Solid Waste Management Planning for Wake County in Consideration of Cost, Energy and Environmental Emissions

Wake County(7/01/14 - 12/31/17)

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Solid Waste Management Planning for Wake County in Consideration of Cost, Energy and Environmental Emissions

Sponsor: Wake County

Start Date: 7/01/14

End Date: 12/31/17

Abstract

The overall objective of the proposed project is to assist the Wake County Solid Waste Division with long-term planning for SWM. SWOLF, a solid waste life-cycle model developed at NCSU, will be utilized to model the county’s current solid waste system and to explore and evaluate future alternatives in consideration of appropriate and county-specific preferences and constraints.

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